TW201732886A - Insulating layer overlying substrate and method of manufacturing same - Google Patents

Abstract

A method for fabricating a germanium-on-insulator substrate includes: providing a first semiconductor substrate; forming a first insulating layer on a top surface of the first semiconductor substrate to form a first semiconductor substrate; and the first semiconductor The substrate is irradiated with a hydrogen ion beam to form a hydrogen doped layer at a predetermined depth from a top surface of the first insulating layer; a second semiconductor substrate is provided; and a second insulating layer is formed on a top surface of the second semiconductor substrate a layer to form a second semiconductor substrate; the first semiconductor substrate is bonded to the second conductor substrate in a face-to-face manner; and the first semiconductor substrate and the second semiconductor substrate are annealed in a heavy hydrogen pressure environment; And separating a portion of the first semiconductor substrate from the second semiconductor substrate to form a semiconductor layer doped with heavy hydrogen on the second semiconductor substrate.

Description

Insulating layer overlying substrate and method of manufacturing same

The invention relates to an insulating layer overlying substrate and a method of manufacturing the same.

In recent years, an insulating layer overlying (SOI) substrate in which a single crystal semiconductor layer is formed on the surface of an insulating material has been used in the industry instead of using a bulk germanium wafer in the fabrication of a semiconductor integrated circuit. Since the use of the SOI substrate is advantageous in that the parasitic capacitance between the drain of the transistor and the substrate can be reduced, thereby improving the performance of the semiconductor integrated circuit.

Regarding the manufacturing method of the semiconductor element, for example, U.S. Patent No. 5,374,564 is to perform hydrogen ion implantation on the germanium wafer by ion implantation, and to form an ion implantation layer at a predetermined depth. Next, a germanium wafer implanted with hydrogen ions is bonded to another germanium wafer, and a hafnium oxide film is interposed between the two germanium wafers. Thereafter, after heat treatment, the ion implantation layer is used as a split surface, and the germanium wafer implanted with hydrogen ions is separated as a film. Thereby, a single crystal germanium layer can be formed over the bonded germanium wafer. For example, U.S. Patent No. 5,872,387, by annealing a substrate on which a gate oxide has been grown in a heavy hydrogen environment, in order to eliminate a dangling bond between the gate oxide and the substrate. However, this method must be carried out at a very high pressure in a heavy hydrogen atmosphere, thus resulting in an increase in manufacturing costs.

In view of the above, there is a need for an improved method of fabricating a germanium-on-insulator substrate to at least improve the above-described deficiency.

The present invention provides an insulating layer overlying germanium substrate and a method of fabricating the same, which can reduce parasitic capacitance between the drain of the transistor and the substrate, and reduce manufacturing costs.

According to an embodiment of the present invention, a method for fabricating a germanium-on-insulator substrate includes: providing a first semiconductor substrate; forming a first insulating layer on a top surface of the first semiconductor substrate to form a first a semiconductor substrate; the first semiconductor substrate is irradiated with an ion beam, Forming a doped layer at a predetermined depth from a top surface of the first insulating layer; providing a second semiconductor substrate; forming a second insulating layer on a top surface of the second semiconductor substrate to form a first a semiconductor substrate; the first semiconductor substrate is bonded to the second conductor substrate in a face-to-face manner; the first semiconductor substrate and the second semiconductor substrate are annealed in a heavy hydrogen pressure environment; and a portion of the first semiconductor is The substrate is separated from the second semiconductor substrate to form a semiconductor layer doped with heavy hydrogen on the second semiconductor substrate.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the first semiconductor substrate comprises a group IV element, a SiGe, a III-V compound, a group III-nitro compound or a II-VI compound.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the predetermined depth is between 0.01 um and 5 um.

The method for manufacturing a germanium-covered overlying substrate, wherein the ion beam is a hydrogen ion beam, the hydrogen ion beam has an accelerating voltage of 1 keV to 200 keV, and the hydrogen ion beam has a doping amount of 10 ¹⁶ (hydrogen) The number of ions / cm ² ) to 2x10 ¹⁷ (number of hydrogen ions / cm ² ).

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the second semiconductor substrate comprises a group IV element, a SiGe, a III-V compound, a group III-nitro compound or a II-VI compound.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the first semiconductor substrate and the second semiconductor are bonded at between 200 and 400 degrees Celsius.

The manufacturing method of the insulating layer on the ruthenium substrate, wherein the step of bonding the first semiconductor substrate and the second semiconductor substrate further comprises: wetting the first insulating layer and the second insulating layer; The first insulating layer and the second insulating layer are in contact with each other; and the first insulating layer and the second insulating layer are contacted with each other such that the first insulating layer is bonded over the second insulating layer.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the heavy hydrogen atmosphere has a gas pressure of between 10 to 1000 Torr.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the semiconductor layer is doped with a concentration of heavy hydrogen of 10 ¹⁰ (number of heavy hydrogen atoms/cm ³ ) to 8× ^{10 18} (number of heavy hydrogen atoms/cm ^{3 )} ).

The method of manufacturing the insulating layer on the germanium substrate, wherein the annealing step further comprises: heating the first semiconductor substrate and the second semiconductor substrate to 600 to 120 degrees Celsius; then cooling the first semiconductor substrate and the The second semiconductor substrate is 400 degrees to 600 degrees Celsius.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the time for heating the first semiconductor substrate and the second semiconductor substrate is between 0.5 hours and 8 hours.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the time for cooling the first semiconductor substrate and the second semiconductor substrate is between 30 minutes and 120 minutes.

The method for manufacturing a germanium-on-insulator substrate, wherein the semiconductor layer doped with heavy hydrogen has a thickness of 50 Å to 50,000 Å.

The method for manufacturing a germanium-covered overlying insulating substrate further includes: after the first semiconductor substrate is separated from the second semiconductor substrate, heating the second semiconductor substrate to 600 to 120 degrees Celsius.

The method for manufacturing a germanium-covered overlying insulating substrate, wherein the heating of the second semiconductor substrate takes between 30 minutes and 8 hours.

According to an embodiment of the present invention, an overlying insulating substrate is provided, comprising: a semiconductor substrate; an insulating layer bonded to a top surface of the semiconductor substrate; and a semiconductor layer doped with heavy hydrogen, A semiconductor layer doped with heavy hydrogen is bonded to the top surface of the insulating layer.

The insulating layer is coated with a germanium substrate, wherein the semiconductor substrate comprises a group IV element, a SiGe, a III-V compound, a group III-nitro compound or a II-VI compound.

The insulating layer is covered with a germanium substrate, wherein the semiconductor layer doped with heavy hydrogen has a thickness of 50 Å to 50,000 Å.

100‧‧‧First semiconductor substrate

102‧‧‧ top surface

104‧‧‧First insulation

106‧‧‧First semiconductor substrate

108‧‧‧Hydrogen ion beam

110‧‧‧ top surface

112‧‧‧ hydrogen doped layer

200‧‧‧second semiconductor substrate

202‧‧‧ top surface

204‧‧‧Second insulation

206‧‧‧Second semiconductor substrate

300‧‧‧Head hydrogen doped bubble block

400‧‧‧Semiconductor layer

FIG. 1 is a flow chart showing a method of manufacturing a germanium-covered insulating substrate provided by the present invention.

2A-2H is a cross-sectional view showing the overlying substrate on which the insulating layer is formed.

The invention is further described below in conjunction with the drawings and the preferred embodiments, but the embodiments of the invention are not limited thereto.

Referring to FIG. 1 , in order to provide a method for fabricating an overlying insulating substrate on an insulating layer, the following steps are included:

S101: providing a first semiconductor substrate

S102: forming a first insulating layer on a top surface of the first semiconductor substrate to form a first semiconductor substrate;

S103: irradiating a first semiconductor substrate with a hydrogen ion beam by using hydrogen as a source gas to form a hydrogen doped layer at a predetermined depth from a top surface of the first insulating layer;

S104: providing a second semiconductor substrate;

S105: forming a second insulating layer on a top surface of the second semiconductor substrate to form a second semiconductor substrate;

S106: bonding the first semiconductor substrate to the second semiconductor substrate face to face;

S107: annealing the first semiconductor substrate and the second semiconductor substrate that are bonded to each other under a deuterium atmosphere;

S108: separating a portion of the first semiconductor substrate from the second semiconductor substrate;

S109: forming a semiconductor layer doped with heavy hydrogen on the second semiconductor substrate.

S110: recycling the separated first semiconductor substrate.

In order to more specifically explain the method of manufacturing the overlying insulating substrate on the insulating layer of FIG. 1, reference is made to FIGS. 2A-2G to provide a cross-sectional view of a germanium-clad substrate on which an insulating layer is provided according to an embodiment of the present invention.

First, referring to FIG. 2A, a first semiconductor substrate 100 is prepared, wherein the material of the first semiconductor substrate 100 may include a group IV element, a SiGe, a group III-V element, a group III-nitro compound or a group II-VI compound. In the present embodiment, the first semiconductor substrate 100 uses a single crystal germanium. In other embodiments, when the material of the first semiconductor substrate 100 is SiGe, the weight percentage of Ge is between 5% and 90%.

Next, referring to FIG. 2B, a first insulating layer 104 is formed on the top surface 102 of the first semiconductor substrate 100 to form a first semiconductor substrate 106, wherein the material of the first insulating layer 104 may include SiO ₂ , SiN or AlN. In the present embodiment, the first insulating layer 104 uses SiO ₂ and has a thickness of approximately 0.1 nm to 500 nm.

Next, referring to FIG. 2C, a hydrogen gas or a hydrogen gas may be used as a source gas, and a plasma of a source gas may be generated by an electric field, and ions contained in the plasma may be taken out from the plasma to generate an ion beam of the source gas. In the present embodiment, the first semiconductor substrate 106 is irradiated with the hydrogen ion beam 108 by using hydrogen as a source gas to form a hydrogen doping layer 112 at a predetermined depth H from the top surface 110 of the first insulating layer 104. The predetermined depth H can be controlled by the acceleration energy of the hydrogen ion beam 108 and the angle of incidence, and the acceleration energy can be controlled by the acceleration voltage and the doping amount. In this embodiment, the predetermined depth H is between 0.01 um and 5 um, the acceleration voltage is between 1 keV and 200 keV, and the doping amount of the hydrogen ion beam is between 10 ¹⁶ (number of hydrogen ions/cm ² ) to 2 x 10 ¹⁷ (hydrogen). Number of ions / cm ² ).

Next, referring to FIG. 2D, a second semiconductor substrate 200 is prepared, wherein the material of the second semiconductor substrate 200 may include a group IV element, a SiGe, a group III-V compound, a group III-nitro compound or a group II-VI compound. In the present embodiment, the material of the second semiconductor substrate 200 is a single crystal germanium.

Next, referring to FIG. 2E, a second insulating layer 204 is formed on the top surface 202 of the second semiconductor substrate 200 to form a second semiconductor substrate 206, wherein the second insulating layer 204 may include SiO ₂ , SiN. Or AlN. In the present embodiment, the second insulating layer 204 uses SiO ₂ and has a thickness of approximately 0.05 nm to 10 nm.

Next, referring to FIG. 2F, the first semiconductor substrate 106 is bonded to the second semiconductor substrate 206 face to face. In this embodiment, the hydrophilic bonding method is used, and the temperature at the time of bonding is between 200 and 400 degrees Celsius, wherein the detailed step of bonding further comprises: first wetting the first insulating layer 104 and the second insulating layer. 204; then, the wetted first insulating layer 104 and the second insulating layer 204 are in contact with each other; and finally applied to the first insulating layer 104 and the second insulating layer 204 such that the first insulating layer 104 and the second insulating layer 204 Tightly joined to each other.

Next, referring to FIG. 2G, the first semiconductor substrate 106 and the second semiconductor substrate 206 bonded to each other are annealed in a deuterium atmosphere. In this embodiment, the heavy hydrogen pressure environment is between 10 Torr and 1000 Torr, and the detailed step of annealing includes: first heating the first semiconductor substrate 106 and the second semiconductor substrate 206 to 600 to 1200 degrees Celsius, and The heating time is about 0.5 to 8 hours; then, the first semiconductor substrate 106 and the second semiconductor substrate 206 are cooled to 400 to 600 degrees Celsius, and the cooling time is about 30 minutes to 120 minutes. After annealing, the originally connected hydrogen doped layer 112 will split. A plurality of mutually spaced heavy hydrogen doped bubble blocks 300 (Bubble formation).

Next, referring to FIG. 2H, a portion of the first semiconductor substrate 106 is separated from the second semiconductor substrate 206 to form a first insulating layer of the semiconductor layer 400 including the heavy hydrogen doped bubble blocks 300. The layer 104 is over the second insulating layer 204, and the semiconductor layer is doped with a concentration of heavy hydrogen of 10 ¹⁰ (number of heavy hydrogen atoms/cm ³ ) to 8× ^{10 18} (number of heavy hydrogen atoms/cm ³ ).

It is worth mentioning that the separated first semiconductor substrate 106 can be further subjected to chemical mechanical polishing (CMP) and cleaning, so that the separated first semiconductor substrate 106 can be recycled, thereby achieving cost-saving effect. The second semiconductor substrate 206 to which the semiconductor layer 400 is bonded may be reheated to 600 to 1200 degrees Celsius, and the reheating time may be between 30 minutes and 8 hours.

Since the dangling bond contains extremely high activity, it is easy to form a trap center, which causes the electron hole pair to be recombined, thereby reducing the resilience of the semiconductor element to the hot carrier effect carrier. The semiconductor element is fabricated by covering the germanium substrate with the insulating layer provided by the present invention, except that the parasitic capacitance between the drain of the transistor and the substrate can be reduced. In the future, when the gate oxide is grown on the insulating layer, the heavy hydrogen atoms (or heavy hydrogen ions) doped into the substrate will diffuse outward to the interface between the gate oxide and the substrate and the semiconductor atoms. Covalently bound to eliminate the levitation bond and efficiently enhance the resilience of the semiconductor component to the hot carrier effect carrier. Moreover, since a high heavy hydrogen pressure is not required, the manufacturing cost is greatly reduced.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the equivalent changes made by the scope of the present invention remain within the scope of the present invention.

Flowchart without symbol

Claims (18)

A method for fabricating a germanium-on-insulator substrate includes: providing a first semiconductor substrate; forming a first insulating layer on a top surface of the first semiconductor substrate to form a first semiconductor substrate; and the first semiconductor The substrate is irradiated with an ion beam to form a doped layer at a predetermined depth from a top surface of the first insulating layer; a second semiconductor substrate is provided; and a second insulating layer is formed on a top surface of the second semiconductor substrate, To form a second semiconductor substrate; the first semiconductor substrate is bonded to the second conductor substrate in a face-to-face manner; the first semiconductor substrate and the second semiconductor substrate are annealed in a heavy hydrogen pressure environment; A portion of the first semiconductor substrate is separated from the second semiconductor substrate to form a semiconductor layer doped with heavy hydrogen on the second semiconductor substrate. The method for producing a germanium-on-insulator substrate according to claim 1, wherein the first semiconductor substrate comprises a group IV element, a SiGe, a group III-V compound, a group III-nitro compound or a group II-VI compound. A method of manufacturing a blanket overlying substrate according to claim 1, wherein the predetermined depth is between 0.01 um and 5 um. The method for fabricating a germanium-on-insulator substrate according to claim 1, wherein the ion beam is a hydrogen ion beam, and the acceleration voltage of the hydrogen ion beam is between 1 keV and 200 keV, and the doping amount of the hydrogen ion beam is between 10 ¹⁶ (number of hydrogen ions / cm ² ) to 2 x 10 ¹⁷ (number of hydrogen ions / cm ² ). The method for fabricating a germanium-on-insulator substrate according to claim 1, wherein the second semiconductor substrate comprises a group IV element, a SiGe, a group III-V compound, a group III-nitro compound or a group II-VI compound. The method of manufacturing a blanket overlying substrate according to claim 1, wherein the first semiconductor substrate and the second semiconductor substrate are bonded face to face at a temperature of between 200 and 400 degrees Celsius. The method for fabricating a germanium-on-insulator substrate according to claim 1, wherein the step of bonding the first semiconductor substrate and the second semiconductor substrate face-to-face further comprises: wetting the first insulating layer and the second insulating layer And contacting the wetted first insulating layer and the second insulating layer with each other; and pressing the first insulating layer and the second insulating layer in contact with each other such that the first insulating layer is bonded to the second Above the insulation. The method for manufacturing a blanket overlying substrate according to claim 1, wherein the heavy hydrogen pressure environment is between 10 Torr and 1000 Torr. The method for fabricating a germanium-on-insulator substrate according to claim 1, wherein the semiconductor layer is doped with a concentration of heavy hydrogen of 10 ¹⁰ (number of heavy hydrogen atoms/cm ³ ) to ⁸ ×10 ¹⁸ (heavy hydrogen atoms) Number / cm ³ ). The method for manufacturing a blanket-on-layer substrate according to claim 1, wherein the annealing step further comprises: heating the first semiconductor substrate and the second semiconductor substrate to 600 to 120 degrees Celsius; and then cooling the first The semiconductor substrate and the second semiconductor substrate are between 400 and 600 degrees Celsius. The method for manufacturing a blanket overlying substrate according to claim 10, wherein the heating of the first semiconductor substrate and the second semiconductor substrate is performed for 0.5 hours to 8 hours. The method for fabricating a germanium-on-insulator substrate according to claim 10, wherein the time for cooling the first semiconductor substrate and the second semiconductor substrate is between 30 minutes and 120 minutes. The method for fabricating a germanium-on-insulator substrate according to claim 1, wherein the semiconductor layer doped with heavy hydrogen has a thickness of 50 Å to 50,000 Å. The method for fabricating a germanium-on-insulator substrate according to claim 1, further comprising the first semiconductor After the substrate is separated from the second semiconductor substrate, the second semiconductor substrate is heated again to 600 to 1200 degrees Celsius. The method for fabricating a germanium-on-insulator substrate according to claim 14, wherein the second semiconductor substrate is heated for a period of time ranging from 30 minutes to 8 hours. An insulating layer overlying a germanium substrate, comprising: a semiconductor substrate; an insulating layer bonded to a top surface of the semiconductor substrate; and a semiconductor layer doped with heavy hydrogen, the semiconductor layer doped with a heavy hydrogen Bonded to the top surface of the insulating layer. The insulating layer according to claim 16, wherein the semiconductor substrate comprises a group IV element, a SiGe, a group III-V compound, a group III-nitro compound or a group II-VI compound. The insulating layer according to claim 16, wherein the semiconductor layer doped with heavy hydrogen has a thickness of 50 Å to 50,000 Å.